Electrical probe



f AU8- I 1950 L. KALoM ELECTRICAL PROBE Filed Jan. 22, 194s Snom/1ro@ ce a//om Lf w.

Nom/e136 Fig. i'.

vLczbzvmevz Patented Aug. l, 1950 UNITED S TATES PATENT OF F I CE ELECTRICAL PROBE c Lawrence Kalom, Chicago, Ill. Application January `22, 1948, Serial No. 3,772

2 claims. V(c1. 12s-2.1)

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0.` G 757) The invention described herein maybe manufactured and used by or for the Government, for governmental purposes, without payment to me of any royalty thereon.

This invention relates to surgical probes and more particularly to electric probes.

In surgery, it is well known that foreign metal objects such as bullets,fragments of shrapnel, pieces of hypodermic needles, etc., are difficult to locate; andcontinued probing frequently endangers the health, if not the life, of the patient.

Often the surgeon does not know whether he is striking the metal object or bone that may be adjacent to it, since they may both give the same feelingr of resistance. This confuses. the surgeon, and necessarily delays` the operation. An`` other undesirable condition which frequently arises is a tendency on the part of the metal object to slide along the tissue planes,` thus Inaking necessary an unusually large incision.

It has hitherto been. proposed to construct surgical probes of a pair of elongate electricallyconductive elements which are electrically insulated from each other and connected through an electrical` circuitwith a signal instrumentality such as a bell. So far as I am aware, these and similar prior art devices, which are known as electric probes, have never been very successful. One reason for their failure is that they have made use of electrodes of` such type as to provide an excessive diametral dimension with the result that as the .penetrating portion of the probe progressed beyondthe `subcutaneous tissue in search of the metalobjech, it` did not readily cut through the fascia, fatty tissue, `fibrous tissue and muscle. This condition is` aggravated in cases where the metal object has been .within the body for a considerable period of time and has therefore become encapsulated in a thick, fibrous sheath.

Another reason for the failure of the` prior art devices referred to is that the; construction and arrangement of their electrodesis such that they must be contactedby the metal `object at a precise angle before `their function isycomplete.

It is among the objects of the present" invention to provide an electric surgical probe` with improved penetrating qualities, whereby probing is rendered less dangerous to the: patient" and less difficult for the surgeon.

Another object is the provision of an electric surgical probe whose electrodes are so constructed and arranged as to permit of their functioning over a relatively wide `range of angles,

thereby 4enabling the comparatively easy location of a foreign metal object.`

Still another object is to provide adevice of the class described which comprises a handle portion containing the signal instrumentality and the operating means therefor, whereby the said device becomes unitary, or entirely selfcontained.

A further object is the provision of a device of the class described which lends itself to sterilization as a unit; and one which also permits of the number of waysin which the principle of the invention may be employed.

In the drawing: Figure 1 is a side elevational view of the complete device of the present invention;

Figure 2 is a view generally similar to that of Figure 1 but showing most of the elements in section, certain other elements being shownin elevation;

Figure 3 is an enlarged longitudinal sectional view of the penetrating instrumentality or probe per se;

Figure 4 is an enlarged fragmentary elevation of the lower portion of the showing of Figure 1, taken at right angles with respect to the latter; and

Figure 5 is a longitudinal sectional view showing fragmentarily, and in enlarged detail, the lower portion of the instrumentality of Figure 3.

The device described below `is an improvement on`my patent which was granted for an Electrical Probe. This Patent No. 2,437,697 was granted March 16, 1948.

The instant device differs from the patent in that the construction shown herein is much simpler than that shown in the patent particularly with respect to the manner `of arrangement for the contact with the battery of the inner electrode.

Referring more particulary to the drawing, the numeral 2 generally designates the penetrating instrumentality, or probe perse, of the device of manner of conventional hypodermic needles,

thereby providingT a sharp cutting extremity. In addition to the bevel 3, the invention comprehends the provision of a corresponding oppositelydisposed bevel 4 which contributes to the sharpness of the cutting extremity, as shown at 5; and has an additional function which will be later described.

The opposite end of the tube 2 is provided with an enlarged tubular head 6 which is exteriorly screw-threaded as at 'I to permit of ready attachment to, and detachment from, a carrying and indicating instrumentality which will be described hereinafter. For assisting such attaching and detaching functions, there is provided a radial ange 8 the periphery of which may be knurled (not shown).

Concentrically disposed within the tube 2 is a round rod 9 which is coextensive therewith. The rod 9 is also composed of a hard electrically-conductive substance which may be of the type described in connection with the tube 2. However, it is to be understood that both of these elements may be formed of other and even respectively different substances; it being only essential that the same be electrically-conductive and comparatively hard. l

For use within a tube 2 of the size specifically set forth hereinbefore, the rod 9 may be approximately 5 mils in diameter, the two elements being maintained in concentric and fixed relationship by an electrical insulating medium Il). This electrical insulating medium may be resinous in nature and applied in the form of one or more coatings; and for this purpose I have found Formvar to be satisfactory. This is the tradename of a polyvinyl formyl resin product of Shawinigan Products Corporation, New York, NewYork. This product belongs to a class of resins known as polyvinyl acetal resins which are prepared by effecting partial or complete hydrolysis of a polyvinyl acetate, followed by orl simultaneously with reaction of the hydrolysis product with an aldehyde. Such compositions possess high dielectric strength, and are commercially obtainable in both plastic and strip form.` The rod 9 is given a light coating of plastic Formvar, which is permitted to dry, then a second and similar coating is applied and before the second coating driesV the rod is inserted in the tube 2. For the insulating material specifically designated, I have found it eicacious to accomplish the drying of the second coating by subjecting the assembled elements (i. e., rod 9 and tube 2) to a temperature'of approximately 175 F. for a period of approximately 10 minutes. In addition to insulating the rod 9 from the tube 2, the Formvai cements the said rod in question.

As previousy mentioned, the rod 9 is coextensive With the tube 2, and the invention contemplates that these elements, and also the electrical insulating medium Il), be so formed as to provide flush surfaces at the oppositely beveled portions 3 and 4 of the tube. This may be accomplished 4 I by simple grinding operations. The tube 2 may. as in the case of a conventional hypodermic needle, be provided With a preformed bevel 3 in which event it would only be necessary to correspondingly grind down the exposed portions of the rod 9 and insulating medium I9. Accordingly, then, only the opposite bevel 4 would require any substantial grinding down of the material of the tube 2; and such an operation may be reduced to a minimum by increasing the angle of the bevel 4 over that of the preformed bevel 3.

The preparation of the corresponding surfaces of the elements in the manner stated immediately hereinbefore provides what would be a common point formed by the tube 2 and rod 9 except for the minute thickness of insulating medium I 0 which separates them. The coextension of the f sharpened extremity of the rod 9 with the cutting extremity 5 of the tube 2 enables them to bridge a metal object disposed in end-on relationship; while the beveled and flush surfaces disposed inwardly thereof promote sensitivity in cases where the metal object is just outside the range of the relationship stated.

Concentrically disposed in the enlarged tubular head 6, and projecting slightly therefrom, is a preformed round plug I2 which is composed of any suitable electrical insulating medium. The plug I2 is maintained in position by an elec- -trical insulating medium I3 which may correspond in substance to the insulating medium I0 and be introduced into the enlarged tubular head 6 while in plastic state and subsequently be permitted to harden. The inner end of the rod 9 extends through the plug I2 and is provided on the exterior thereof with a hooked end I4, the extremity of which is embedded in the outer face of the plug.

As described earlier herein, the present invention contemplates the carrying of the tube 2 and associated instrumentalities by a handle portion containing the signal instrumentality and the operating means therefor. Accordingly, there is vprovided a tubular metallic flash-light case I6 having a screw-threaded opening therein for receiving the exteriorly screw-threaded portion I of the enlarged tubular head 6 of the tube 2.

Between the end of the flash-light case I6 and the adjacent surface of the radial flange 8 of the enlarged tubular head 6 there is disposed a gasket I8 for providing a water-tight connection. The other end of the hash-light case I6 is interiorly screw-threaded, as at I9, to receive an exteriorly screw-threaded ferrule 20. This ferrule 20 is centrally bored and screw-threaded, as at 2I, to receive the screw-threaded shank of the usual flash-light bulb 22.

Within the case I6 is a ash-light battery 23 which is in electrical relation at its opposite ends with the hooked-end I4 of the rod 9 and the metallic contact element of flash-light 22. The slight projection of the outer end of the plug I2 beyond the end of the enlarged tubular head 6 insures the spacing of the latter from the adjacent end of the battery 23, thereby eliminating possibility of short-circuiting at 'this point.

This application is a continuation-in-part of my previous application Serial No. 658,725, filed April 1, 1946, which application has matured into the aforesaid Patent No. 2,437,697 issued March 16, 1948. In this patent, the tubular portion of the probe contacts a slidably movable pin which is connected conductively to the battery by a spring, whereas in the present construction there is direct contact between the central electrode,

that is the rod 9, and the battery 23, there resulting herein a simplified construction as compared with the arrangement of parts shown and described in the said patent.

The ferrule 2U is also provided with an exteriorly screw-threaded portion 24, of reduced diameter, which enables the attachment thereto of an interiorly screw-threaded cap 25 of translucent material. Either the flash-light bulb 22 and/or the translucent cap 25 is so colored as to cast a light which is readily distinguishable in the bright, white light of a surgical operating room. Intermediate its ends the ferrule is provided with a radial flange 2B between which and the adjacent ends of the flash-light case I6 and the cap are gaskets 21 for providing Watertight connections.

In operation; Electric current flows from the vbattery 23 to the bulb 22; down the side of the flash-light case I6; and down the tube 2 to the sharpened extremity thereof. Current cannot get back to the base of the battery 23 to complete the circuit until the contact surfaces of the tube 2 and the rod 9 are bridged by an electrically conductive object; at which time the bulb 22 will be illuminated.

The end of the needle is beveled approximately at 45 to its longitudinal axis and terminates in a probing point 5 disposed off-center from the longitudinal axis, with a portion I0' of the insulation lll being brought to a common point with the point 5. With this construction there is formed la highly sensitive point which will respond when striking a metallic foreign body in the tissues being probed at a substantially vertical angle,

In operation, the operator rotates the instrument in opposite directions with his ngers, through about an eighth of a turn for increasing the sensitivity of the tip. In practice it is found that approximately .003 inch thickness of insulation is suflicient.

Other modes of applying the principles of the invention may be employed, changes being made as regards the details described, providing the features stated in anyof the following claims, or the equivalent of such, be employed.

Having thus described my invention, what I claim as new and Wish to secure by Letters Patent is:

1. A surgical probe comprising an nteriorly insulated tubular handle portion adapted to retain a source of electrical energy therein, a signal lamp operated by said source of energy and positioned at one end of said handle, a tubular tapered head fitted within the opposite end of said tubular handle, said head extending into a slender needle-shaped probe, tapered at its end to form an insertion point, an insulated central electrode contained within said probe, tapered at one extremity flush with the tapering of the probe, and at its opposite end extending within the enlarged tapered portion of the head, a plug of insulating material surrounding said. extremity of the central electrode and a retaining body of insulating material partially surrounding said plug and a portion of said central electrode to retain them in desired position Within the tapered head.

2. A surgical probe comprising an nteriorly insulated tubular handle portion adap-ted to retain a source of electrical energy therein, a signal lamp operated by said source of energy and positioned at one end of said handle, a tubular tapered head fitted within the opposite end of said tubular handle, said head extending in a slender needle-shaped probe, tapered at its end to form an insertion point, an insulated central electrode contained within said probe, tapered at one extremity flush With the tapering of the probe, and at its opposite end extending within the enlarged tapered portion of the head, a plug of insulating material surrounding said extremity of the central electrode, the said electrode having a hook formed at its upper end which is: bent into the upper surface of the plug, and a retaining body of insulating material partially surrounding said plug and a portion of said central electrode to retain them in desired position within the tapered head.

LAWRENCE KALOM.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,437,697 Kalom Mar. 16, 1948 FOREIGN PATENTS Number Country Date 132,880 Austria Apr. `25, 1933 

